Based on a play by Patrick Hamilton, two students murder a fellow student before a party with his father and friends.
Brandon Shaw (John Dall) and Phillip Morgan (Farley Granger) strangle David Kentley and put his body in a chest. Brandon is confident they have committed the perfect murder, but Phillip has doubts. They celebrate with champagne before their party. Brandon suggests they put supper on the chest. Phillip sees the rope, and Brandon yanks it out. Mrs. Wilson (Edith Evanson) arrives and complains about using the chest. Ken Lawrence (Douglas Dick) comes in and says he is washed up with Janet and that she likes David. Janet Walker (Joan Chandler) arrives and complains that Brandon invited Ken.
Mr. Kentley (Cedric Hardwicke) arrives with Mrs. Atwater (Constance Collier) because his wife is sick. He asks if David is there. Phillip plays piano, and their teacher Rupert Cadell (James Stewart) comes in. He asks Brandon about the champagne and the chest. Brandon explains that Phillip does not eat chicken because he used to strangle them. Phillip objects and denies it. Rupert says he approves of murder by superior people. Mr. Kentley disapproves, but Brandon defends Rupert's idea. Rupert asks Brandon if he is planning to kill inferior people.
Janet and Ken wonder about Brandon, who told Ken he would have a better chance with Janet. Mrs. Wilson tells Rupert how Brandon and Phillip have been acting strangely. Rupert asks Phillip what is going on and why he lied. Mr. Kentley's books are tied with the rope, and Phillip gets upset. Phillip tells Brandon that Rupert is suspicious.
Mrs. Wilson clears off the chest while others wonder where David is. Brandon stops her from opening the chest. Mr. Kentley wants to go home, and Janet asks Ken to go with them. Rupert picks up the wrong hat before leaving. Phillip drinks and argues with Brandon. Mrs. Wilson asks for a key and leaves.
Phillip is scared when Rupert calls to come back up. Brandon gets a gun and lets Rupert in. Rupert hides his cigarette case on the chest and then finds it. Rupert has a drink and wonders about David. Rupert says that Janet suspects that Brandon kidnapped David. Brandon asks Rupert how he would do it. Rupert reconstructs the crime, and Phillip breaks his glass. Rupert notices Brandon has a gun, and Brandon puts it on the table. Rupert pulls out the rope, and Phillip confesses and wants to kill Brandon and Rupert. Phillip has the gun, but Rupert struggles with him and gets it. Rupert looks into the chest. Brandon explains it is Rupert's theory lived. Rupert says that Brandon twisted his words, and he lectures him for his murder. Rupert says that society will see that both die. Rupert opens the window and shoots three times. Police sirens are heard, and Phillip says they are coming.
This psychological drama explores the perverted theory
of Leopold and Loeb that those with superior intellects have the
right to murder the inferior. When their teacher learns they have
acted on his theories, he realizes how immoral they are.